Microplastic in the salt, a warning from Greenpeace

36 of the 39 samples of kitchen salt analyzed, from various countries, contained 5 millimeters or smaller plastic fragments, better known as microplastics. These are the results of a recent scientific research, published in the international journal Environmental Science & Technology, born from the collaboration between Greenpeace and the University of Incheon in South Korea. From the survey, which examined samples of sea salt, mine and lakes' one, it turns out that 36 samples were contaminated with microplastics like Polyethylene, Polypropylene and Polyethylene Terephthalate.

This research, the first on a so large scale and appropriate to allow a comparative analysis of the presence of microplastics in samples of kitchen salt from many geographical areas, has also allowed to correlate the levels of pollution found in salt with the introduction and the release of plastic into the environment. Indeed, among all the samples analyzed, those from Asia recorded the highest average levels of contamination with peaks up to 13 thousand microplastics in a sample coming from Indonesia which, according to recent studies, is the second global contributor of plastic in the seas.

In the samples of sea salt was observed a greater presence of microplastics (between 0 and 1674 microplastics per kilo, excluding the Indonesian sample), followed by samples from salt lakes (between 28 and 462 microplastics per kilo) and from mines (between 0 and 148 microplastics per kilo). Moreover, according to the results of the research and considering the average daily intake of 10 grams, an adult could ingest, only through the consumption of kitchen salt, about 2 thousand pieces of microplastics a year considering also the average microplastic concentration in all the salts analyzed.

«The results suggest that the ingestion of micro-plastics by humans could also occur through products of marine origin and human exposure may depend on levels of contamination in different geographical areas», said Kim Seung-Kyu, a professor at the University of Incheon and author of the article. «To limit our exposure to microplastics - he concluded - preventive measures are needed, regarding the introduction of plastics into the sea, better management of waste in the terrestrial environment and, above all, the reduction of plastic waste production».